How does a seismograph measure an earthquake and what is the process involved in detecting seismic activity?

A seismograph measures an earthquake by detecting and recording the vibrations caused by the movement of the Earth's crust. When an earthquake occurs, the seismograph's sensors pick up the seismic waves and produce a graphical representation called a seismogram. This helps scientists analyze the earthquake's magnitude, location, and depth. The process involves placing seismographs in different locations to detect and record seismic activity, which is then analyzed to understand the earthquake's characteristics.